I have a drawer controller connected to 2 pipes with gates (Buildcraft)

• Pipe A (INPUT): Gets items from a chest every time I drop one item inside.
• Pipe B (OUTPUT): Extracts from my drawers several wood items to feed a generator whenever it needs fuel.

If pipe B is active (extracting items) and at the same time I deposit some items in my chest, pipe A will get those items and instead of putting them in my drawers, the drawer controller will drop the items to the ground.

As soon as pipe B stops extacting everything works as expected.

Actually the error is this one #271
I just noticed that after a world load the pipe wasn't connected to the machine, that's why the items were being dropped to the ground.